基于焊槍姿態(tài)與熔池局部流態(tài)測量的焊工行為研究
發(fā)布時間：2018-08-06 21:31
【摘要】：近年來,隨著深海資源開發(fā)中管道的全位置焊接、核工業(yè)設(shè)備中密閉空間內(nèi)構(gòu)件的焊接以及空間站真空、失重條件下等極限環(huán)境中焊接的加速發(fā)展,一方面這些極限環(huán)境中對焊接質(zhì)量要求高,另一方面在極限環(huán)境焊接過程中危險系數(shù)極高,焊工難以在現(xiàn)場手工操作。而就目前而言對于人工智能、焊接環(huán)境的識別、問題規(guī)劃的研究不夠透徹,還不能使機(jī)器人在陌生環(huán)境中脫離焊工而自主進(jìn)行焊接作業(yè)。因此急切需要新一代智能化控制焊接機(jī)器人代替焊工在危險環(huán)境中進(jìn)行焊接操作。在焊接過程中熔池液態(tài)金屬表面承載著眾多能夠反映焊接質(zhì)量、焊縫成形的特征參數(shù)信息,如熔透狀態(tài),熔寬比等。要想焊接機(jī)器人像優(yōu)秀的焊工一樣對熔池進(jìn)行穩(wěn)定控制,我們需要解析焊接過程中的焊工行為,使焊工行為移植于焊接機(jī)器人。因此測量熔池表面特征參數(shù)對于研究熔池表面物理信息動態(tài)變化行為,提高焊接質(zhì)量,對智能化焊接機(jī)器人發(fā)展具有十分重要的理論意義和工程應(yīng)用前景。本文利用GTAW熔池表面與金屬母材對光的反射方式不同這一原理,采用激光視覺法,從以下幾方面對熔池動態(tài)變化過程中的焊工行為進(jìn)行了研究:(1)根據(jù)激光視覺法測量原理,設(shè)計了焊槍、激光器、成像屏以及焊槍姿態(tài)傳感器夾具,建立了激光視覺與焊槍姿態(tài)傳感試驗(yàn)系統(tǒng),搭建了用于測量熔池表面特征參數(shù)信息的實(shí)驗(yàn)平臺,實(shí)現(xiàn)了對熔池表面動態(tài)變化特征參數(shù)信息的測量。(2)通過采集到的GTAW熔池自由表面反射的激光條紋圖像,采用所設(shè)計的算法對成像屏上激光條紋亮度進(jìn)行了求解,通過對比分析焊接速度、焊接電流、電弧弧長、焊槍姿態(tài)調(diào)整下的熔池表面反射激光條紋在成像屏上聚集程度的變化規(guī)律發(fā)現(xiàn),焊接規(guī)范單一調(diào)節(jié)時,焊接過程中熔池穩(wěn)定性差,焊縫成形也比較差,反射激光條紋亮度變化大。對比于焊工對焊槍姿態(tài)的調(diào)整,焊槍姿態(tài)調(diào)整容易使熔池達(dá)到穩(wěn)定狀態(tài),而且焊縫成形好,焊接過程中成像屏上激光條紋亮度變化小。實(shí)驗(yàn)結(jié)果表明獲得良好焊縫成形更需要較高的焊接技能和更豐富的焊接經(jīng)驗(yàn)。(3)為了說明焊接過程中隨著焊縫熔透狀態(tài)的變化,投射于熔池表面的激光條紋經(jīng)熔池表面反射后在成像屏上聚集狀態(tài)的不同,對焊接電流和電弧弧長變化對熔透的作用進(jìn)行了仿真計算,仿真計算結(jié)果表明,所建立的數(shù)學(xué)模形能夠反映焊接電流和電弧弧長對熔透狀態(tài)的作用過程,而且隨著熔透程度越來越大,熔池表面塌陷,這時熔池表面不再是一個半球面,激光條紋反射過程條紋在凹陷的熔池表面多次反射而使成像屏上的條紋聚集,而且仿真計算結(jié)果表明了焊接電流對熔透狀態(tài)的作用更加顯著。(4)通過GTAW工藝試驗(yàn),采用所設(shè)計的算法計算了熔池表面反射激光條紋的曲率半徑,研究了在焊工焊接過程中熔池表面動態(tài)變化以及熔池液態(tài)金屬局部流態(tài)變化。結(jié)果表明,在熔池中心,激光條紋曲率半徑變化率最大,遠(yuǎn)離熔池中心,激光條紋曲率半徑變化率越來越小。從激光條紋曲率半徑變化率趨勢可以說明在焊接過程中,熔池中心位置處表面變形大,流動速率大。而且從曲率半徑變化率這一特征參數(shù)可以反映熔池在XOZ面上的局部流態(tài),靠近熔池中心,其流速較大,沿中心向邊緣流速逐漸減小。這一研究將為進(jìn)一步測量熔池液態(tài)金屬流態(tài)提供一種新的途徑,從而將為機(jī)器人焊接過程的智能化控制提供一種新方法。
[Abstract]:In recent years, with the full position welding of pipelines in the development of deep sea resources, the welding of the components in the closed space in the nuclear industrial equipment, the vacuum of the space station and the heavy condition in the extreme environment, the welding quality is high in these extreme environment, on the other hand, the dangerous coefficient is very high in the process of extreme environment welding. At present, the welder is difficult to manually operate in the field. But at present, the research on the identification of artificial intelligence, welding environment and the problem planning are not thorough enough, and the robot can not make the welding work independently in the strange environment. Therefore, a new generation of intelligent control welding robot is urgently needed to replace the welder in the dangerous environment. In the process of welding, the liquid metal surface of the molten pool is loaded with a number of characteristic parameters, such as penetration status, melting width ratio, etc., which can reflect welding quality and weld formation, such as penetration and width ratio. Therefore, it is very important for the development of the intelligent welding robot to measure the surface characteristic parameters of the molten pool and to improve the quality of the welding surface and improve the welding quality. In this paper, the reflection mode of the light is different from the surface of the GTAW pool and the metal material. One principle, using laser vision method, the welder behavior in the process of dynamic change of molten pool is studied from the following aspects: (1) according to the principle of laser vision measurement, the welding gun, laser, imaging screen and welding gun attitude sensor fixture are designed, and the attitude sensing test system of laser vision and welding gun is set up, and used to measure the molten pool. The experimental platform of the surface characteristic parameter information realizes the measurement of the characteristic parameter information of the dynamic change of the molten pool surface. (2) the laser stripe luminance on the imaging screen is solved by the designed algorithm, and the welding speed, welding current and arc are compared and analyzed by the designed algorithm. (2) the laser stripe image reflected from the free surface of the molten pool is collected. When the arc length is long, the changing rule of the laser stripe reflected on the surface of the weld pool on the surface of the welding tank under the attitude adjustment of the welding gun shows that when the welding code is single, the stability of the weld pool is poor, the weld formation is poor and the brightness of the reflected laser stripe varies greatly. The adjustment of the welding gun attitude and the adjustment of the welding gun attitude are easy to be made. The weld pool is stable, and the weld is formed well. The brightness of the laser stripe on the screen is small in the process of welding. The experimental results show that the good weld formation needs higher welding skills and more abundant welding experience. (3) in order to explain the laser strip projected on the surface of the weld pool with the change of the weld penetration state during the welding process. The effect of welding current and arc length change on the penetration of the welding current and arc length is simulated. The simulation results show that the mathematical model can reflect the process of welding current and arc length to the penetration state, and as the penetration degree is increasing, the melting is more and more melting. The surface of the pool is collapsing, and the surface of the pool is no longer a hemispherical surface, and the stripe of the laser stripe reflects on the surface of the sink on the surface of the sink to gather the stripes on the imaging screen. And the simulation results show that the effect of the welding current on the penetration state is more significant. (4) through the GTAW process test, the designed algorithm is used. The curvature radius of the laser stripe is reflected on the surface of the molten pool. The dynamic changes of the molten pool surface and the change of the liquid metal flow in the weld pool are studied. The results show that the curvature radius of the laser stripe is the largest in the center of the molten pool, and the curvature radius of the laser stripe is getting smaller and smaller. The change rate trend of curvature radius can indicate that during the welding process, the surface deformation and flow rate of the center of the weld pool are large and the flow rate is large. And the characteristic parameters of the curvature radius change rate can reflect the local flow on the XOZ surface, which is close to the center of the molten pool, and the flow velocity decreases gradually along the center to the edge. One-step measurement of liquid metal flow in molten pool provides a new way for intelligent control of robot welding process.
【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG44
[Abstract]:In recent years, with the full position welding of pipelines in the development of deep sea resources, the welding of the components in the closed space in the nuclear industrial equipment, the vacuum of the space station and the heavy condition in the extreme environment, the welding quality is high in these extreme environment, on the other hand, the dangerous coefficient is very high in the process of extreme environment welding. At present, the welder is difficult to manually operate in the field. But at present, the research on the identification of artificial intelligence, welding environment and the problem planning are not thorough enough, and the robot can not make the welding work independently in the strange environment. Therefore, a new generation of intelligent control welding robot is urgently needed to replace the welder in the dangerous environment. In the process of welding, the liquid metal surface of the molten pool is loaded with a number of characteristic parameters, such as penetration status, melting width ratio, etc., which can reflect welding quality and weld formation, such as penetration and width ratio. Therefore, it is very important for the development of the intelligent welding robot to measure the surface characteristic parameters of the molten pool and to improve the quality of the welding surface and improve the welding quality. In this paper, the reflection mode of the light is different from the surface of the GTAW pool and the metal material. One principle, using laser vision method, the welder behavior in the process of dynamic change of molten pool is studied from the following aspects: (1) according to the principle of laser vision measurement, the welding gun, laser, imaging screen and welding gun attitude sensor fixture are designed, and the attitude sensing test system of laser vision and welding gun is set up, and used to measure the molten pool. The experimental platform of the surface characteristic parameter information realizes the measurement of the characteristic parameter information of the dynamic change of the molten pool surface. (2) the laser stripe luminance on the imaging screen is solved by the designed algorithm, and the welding speed, welding current and arc are compared and analyzed by the designed algorithm. (2) the laser stripe image reflected from the free surface of the molten pool is collected. When the arc length is long, the changing rule of the laser stripe reflected on the surface of the weld pool on the surface of the welding tank under the attitude adjustment of the welding gun shows that when the welding code is single, the stability of the weld pool is poor, the weld formation is poor and the brightness of the reflected laser stripe varies greatly. The adjustment of the welding gun attitude and the adjustment of the welding gun attitude are easy to be made. The weld pool is stable, and the weld is formed well. The brightness of the laser stripe on the screen is small in the process of welding. The experimental results show that the good weld formation needs higher welding skills and more abundant welding experience. (3) in order to explain the laser strip projected on the surface of the weld pool with the change of the weld penetration state during the welding process. The effect of welding current and arc length change on the penetration of the welding current and arc length is simulated. The simulation results show that the mathematical model can reflect the process of welding current and arc length to the penetration state, and as the penetration degree is increasing, the melting is more and more melting. The surface of the pool is collapsing, and the surface of the pool is no longer a hemispherical surface, and the stripe of the laser stripe reflects on the surface of the sink on the surface of the sink to gather the stripes on the imaging screen. And the simulation results show that the effect of the welding current on the penetration state is more significant. (4) through the GTAW process test, the designed algorithm is used. The curvature radius of the laser stripe is reflected on the surface of the molten pool. The dynamic changes of the molten pool surface and the change of the liquid metal flow in the weld pool are studied. The results show that the curvature radius of the laser stripe is the largest in the center of the molten pool, and the curvature radius of the laser stripe is getting smaller and smaller. The change rate trend of curvature radius can indicate that during the welding process, the surface deformation and flow rate of the center of the weld pool are large and the flow rate is large. And the characteristic parameters of the curvature radius change rate can reflect the local flow on the XOZ surface, which is close to the center of the molten pool, and the flow velocity decreases gradually along the center to the edge. One-step measurement of liquid metal flow in molten pool provides a new way for intelligent control of robot welding process.
【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG44
【參考文獻(xiàn)】
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